view packages/language/c/libm/current/src/float/portable-api/sf_modf.c @ 3337:77f9d3253c3e

Add: Complex number header and library (single and double precision floating point), port from Newlib. Add: Single precision floating point library, port from Newlib. [ Bugzilla 1001539 ]
author vae
date Sun, 25 Aug 2013 14:38:57 +0000
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//===========================================================================
//
//      sf_modf.c
//
//      Part of the standard mathematical function library
//
//===========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 2012 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later
// version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License
// along with eCos; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// As a special exception, if other files instantiate templates or use
// macros or inline functions from this file, or you compile this file
// and link it with other works to produce a work based on this file,
// this file does not by itself cause the resulting work to be covered by
// the GNU General Public License. However the source code for this file
// must still be made available in accordance with section (3) of the GNU
// General Public License v2.
//
// This exception does not invalidate any other reasons why a work based
// on this file might be covered by the GNU General Public License.
// -------------------------------------------
// ####ECOSGPLCOPYRIGHTEND####
//===========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):
// Contributors: visar, ilijak
// Date:        2012-03-08
// Purpose:
// Description:
// Usage:
//
//####DESCRIPTIONEND####
//
//===========================================================================

// CONFIGURATION

#include <pkgconf/libm.h>   // Configuration header

// Include the Math library?
#ifdef CYGPKG_LIBM

// Derived from code with the following copyright


/* sf_modf.c -- float version of s_modf.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */


#include "mathincl/fdlibm.h"

#ifdef __STDC__
static const float one = 1.0;
#else
static float one = 1.0;
#endif

#ifdef __STDC__
	float modff(float x, float *iptr)
#else
	float modff(x, iptr)
	float x,*iptr;
#endif
{
	__int32_t i0,j0;
	__uint32_t i;
	i0 = CYG_LIBM_WORD(x);
	j0 = ((i0>>23)&0xff)-0x7f;	/* exponent of x */
	if(j0<23) {			/* integer part in x */
	    if(j0<0) {			/* |x|<1 */
	        SET_FLOAT_WORD(*iptr,i0&0x80000000);	/* *iptr = +-0 */
		return x;
	    } else {
		i = (0x007fffff)>>j0;
		if((i0&i)==0) {			/* x is integral */
		    __uint32_t ix;
		    *iptr = x;
		    ix = CYG_LIBM_WORD(x);
		    SET_FLOAT_WORD(x,ix&0x80000000);	/* return +-0 */
		    return x;
		} else {
		    SET_FLOAT_WORD(*iptr,i0&(~i));
		    return x - *iptr;
		}
	    }
	} else {			/* no fraction part */
	    __uint32_t ix;
	    *iptr = x*one;
	    ix = CYG_LIBM_WORD(x);
	    SET_FLOAT_WORD(x,ix&0x80000000);	/* return +-0 */
	    return x;
	}
}

#endif // ifdef CYGPKG_LIBM

// EOF sf_modf.c